Vehicle door latch systems, such as, but not limited to, door latch systems for helicopters and other aircraft comprise features configured to positively hold a latch in either a locked position or an unlocked position. It can be particularly important that door latch systems used with helicopters and other aircraft do not accidentally become unlatched so that doors do not open during flight unless intended to be opened. Some doors remaining closed is a safety of flight issue which requires latches that are fail-safe from inadvertently opening in flight. While some door latch systems utilize an overcenter feature to maintain a door latch in an open position or a closed position, some overcenter features require utilization of complicated, expensive, and/or heavy components or can inadvertently unlatch.